Embodiments relate to a semiconductor device, and more particularly, to a semiconductor device for improving light efficiency.
A semiconductor device including a compound such as GaN and AlGaN has various advantages such as wide and adjustable band gap energy, and thus may be variously used as a light emitting element, a light receiving element, various diodes, and the like.
In particular, the light emitting element such as a light emitting diode and a laser diode using group 3-5 or group 2-6 compound semiconductor materials may implement various colors such as red, green, blue, and ultraviolet rays with development of a thin film growth technique and a device material, may also implement an efficient white ray by using fluorescent materials or combining colors, and has advantages such as low power consumption, a semipermanent lifespan, a fast response speed, safety, and environmental friendliness, as compared to the existing light source such as a fluorescent lamp and an incandescent lamp.
In addition, when the light receiving element such as a photo-detector and a solar cell is manufactured using group 3-5 or group 2-6 compound semiconductor materials, the light receiving element generates a photocurrent by absorbing light beams having various wavelengths with development of a device material, and thus may use light beams having various wavelengths ranging from gamma rays to radio waves. Also, the light receiving element has advantages such as a fast response speed, safety, environmental friendliness, and easy adjustment of a device material, and thus may be also easily used for power control, a microwave circuit, or a communication module.
Thus, the semiconductor device has been widely applied to a transmission module of an optical communication means, a light emitting diode backlight unit replacing a cold cathode fluorescence lamp (CCFL) constituting a backlight unit of a liquid crystal display (LCD) device, a white light emitting diode lighting device replacing a fluorescent lamp and an incandescent lamp, a head lamp for a vehicle, a traffic light, a sensor configured to detect gas or fire, and the like. Also, the semiconductor device may be extensively applied to a high frequency application circuit, other power control devices, and a communication module.
In particular, high output is required for the semiconductor device provided in the head lamp for the vehicle. Accordingly, the semiconductor device generates a high current to implement a high output lamp. Accordingly, in the semiconductor device, a current and heat are focused on an area adjacent to a pad to shorten a lifespan of an active layer region, thereby causing deterioration of reliability.